The manufacture of laminated rubber and synthetic rubber products like tires and drive belts is commonly accomplished using a drum-transfer building technique. This technique involves the use of a “building drum” on which components of the product are assembled, and a number of “measuring” or “measuring” drums from which components of the product are transferred to the building drum. Each component of the product is initially placed onto the surface of a measuring drum at a “work station” and is cut to the right length. The measuring drum is then moved towards the building drum until the component contacts the building drum. The rotation of the building drum with respect to the measuring drum causes the component to transfer from the measuring drum to the building drum. An example of a measuring drum is disclosed in U.S. Pat. No. 4,504,337. In an automatic tire building system, such as disclosed in U.S. Patent Application entitled METHOD FOR MANUFACTURING TIRES ON A FLEXIBLE MANUFACTURING SYSTEM, the building drum travels from work station to work station, receiving one or more components at each work station until the product (or a subassembly thereof) is completed on the building drum. In this tire building system, a plurality of building drums are employed in “pipeline” fashion such that at any given time there are building drums in process at different work stations or in transit between stations, each drum serially acquiring product components.
This drum-transfer process is shown schematically in FIGS. 1A–1C. FIG. 1A shows a drum-transfer assembly portion 10 of a work station wherein a measuring drum 12 has had a tire component 14 placed on the surface thereof and the component 14 has been cut to length. A building drum 16 is in position, spaced away from the measuring drum 12, awaiting transfer of the product component 14. The measuring drum 12 and building drum 16 are placed in contact with each other, as shown in FIG. 1B. The measuring drum 12 and the building drum 16 are rotated in coordination with one another to cause the component 14 to release from the measuring drum 12 and adhere to the building drum 16. Once the transfer of the component 14 to the building drum 16 is complete, the measuring drum 12 and building drum 16 are spaced from each other in preparation for receiving a new component 14, as shown in FIG. 1C.
Typically, one or more tire components 14 are applied to the building drum 16 from the measuring drum(s) at each work station. When two of the same type but spaced tire components are assembled onto the tire building drum at the same work station, it has been difficult to apply them both at the same station, especially when the two spaced-apart narrow components 14 are close to each other. An example of applying two components is the assembly of two tire inserts of a runflat tire, wherein the two insert components are transferred to the building drum from two measuring drums at the same work station.
A two-component assembly technique of this type is illustrated schematically in FIG. 2. FIG. 2 shows a top view of a portion 10A of a two-component work station comprising a pair of narrow measuring drums 12A and 12B positioned side by side, each having been prepared with a respective tire component 14A and 14B, such as tire insert components, for transfer to a waiting building drum 16.
Two-component assembly at a single work station has at least two significant advantages over single component assembly: speed of assembly and conservation of manufacturing floor space. Multiple component assembly, however, is limited by the number of measuring drums that can be positioned side by side in a work station and by the position of the components within the product. If the components must be placed very close to one another on the building drum, it is not possible to position two measuring drums closely enough together in a side by side configurations to place both components in their correct positions.
It would be advantageous, however, if there were a way to assemble multiple, narrow, closely-spaced components of a tire construction onto a tire building drum at the same work station, since the size and cost of separate work stations and additional assembly time is disproportionate to the size, cost and value of some narrow components.
As an example, where several narrow components, such as a bead filler and a support strip are both located in the bead area of a vehicle tire are narrow, it is possible to assemble the two bead filler components at one work station and the two narrow support strips at another work station. Using prior-art techniques it is not possible, however, to assemble the both the support strips and the bead filler components at the same assembly station, since the bead filler component is assembled at least partially on top of the support strip component, preventing the use of side by side measuring drums.
In view of the aforementioned difficulty in assembling multiple, closely-spaced, narrow components at a single work station, and in light of the clear advantages of doing so, there is an ongoing need for improved drum-transfer assembly techniques.